High capacity sheet feeder

Abstract

This invention discloses a sheet feeder which comprises a plurality of micro switches, a light sensitive switch, and a controller board having an erasable programmable read only memory (EPROM) for receiving signals from the micro switch and sending pre-programmed responses to control the movement a pair of motors which in turn cause a paper carrying elevator to ascend and send the feed paper sheets into a laser printer. The capacity of the sheet feeder of this invention is several times that of a conventional tray-shaped sheet feeder. The front face of this sheet feeder is provided with a receiving rack, each of whose two ends is furnished with an oblong hole. A sheet guide is pivotally connected to the sheet feeder using two small round bolts inserted through the two oblong holes respectively. The height of the sheet guide can be adjusted within a given limit to accommodate the varying feeding port height of a wide variety of laser printers. The sheet guide can be folded down completely against the front face of the sheet feeder to provide packing and shipping convenience.

What is claimed is: 
     
       1. A high capacity sheet feeder adapted for use with a laser printer, comprising: (a) a paper carrying elevator;   (b) a first motor to cause said paper carrying elevator to move upward and downward;   (c) a host computer board;   (d) a plurality of micro switches in cooperation with said host computer board for controlling the upward or downward movement of said first motor;   (e) a second motor for delivering paper from said sheet feeder to said laser printer;   (f) a sheet guide for directing said paper from said sheet feeder to a feeding port of said laser printer;   (g) a light sensitive switch in said sheet guide, which, in cooperation with said host computer board, will actuate said second motor; and   (h) an adjusting means for pivotally adjusting said sheet guide so as to allow said sheet feeder adaptable for use with a wide variety of laser printers having feeding ports at varying heights.   
     
     
       2. The high capacity sheet feeder of claim 1 wherein said host computer board contains a built-in program for carrying out pre-determined operations. 
     
     
       3. The high capacity sheet feeder of claim 2 wherein said built-in program is provided in the form of an erasable programmable read-only memory, or EPROM. 
     
     
       4. The capacity sheet feeder of claim 1 wherein said adjusting means comprises: (a) a receiving rack fixedly mounted on said sheet feeder;   (b) an oblong hole at each end of said receiving rack;   (c) a pair of round holes in said sheet guide, each of said round holes is disposed so as to match a corresponding said oblong hole in said receiving rack;   (d) a pair of round bolts, each of said round bolts being adapted to tie one of said round holes with a corresponding oblong hole thereby affixing said sheet guide to said receiving rack while allowing said sheet guide to pivot about said round bolts; and   (e) a pair of E-shaped retaining rings for fastening said round bolts in place.